Interpretive Summary: Infection by the protozoan (single celled) parasite, Toxoplasma gondii is widely prevalent in man and animals. It causes mental retardation and loss of vision in children and abortion in livestock. Toxoplasmosis is rarely symptomatic in dogs. Until 1988, many cases of clinical toxoplasmosis were probably due to another closely related parasite, Neospora caninum. Diagnosis of toxoplasmosis is rarely made in live dogs. Scientists at the Beltsville Agriculture Research Center and the Auburn University report antibody responses by using different tests in dogs fed tissue cysts of Toxoplasma. The findings will be useful for veterinarians to diagnose toxoplasmosis in dogs.

Technical Abstract:
Tissue cyst induced Toxoplasma gondii infections were examined in 2 beagle dogs orally inoculated with tissue cysts. Neither dog developed clinical signs of toxoplasmosis. Both dogs developed low antibody titers to T. gondii. The MAT and IFAT were superior to the LAT and IHT tests for detecting antibodies to T. gondii.